FORT MEADE, Md. - U.S. Army Pfc. Bradley Manning has been acquitted of aiding the enemy for giving classified secrets to WikiLeaks.

The military judge hearing the case, Army Col. Denise Lind, announced the verdict Tuesday. The charge was the most serious of 21 counts. It carried a possible life sentence without parole.

Manning was convicted of five espionage counts, five theft charges, a computer fraud charge and other military infractions.

Manning's sentencing hearing is set to begin Wednesday.

The 25-year-old Crescent, Okla., native acknowledged giving the anti-secrecy website hundreds of thousands of battlefield reports, diplomatic cables and videos in early 2010.

Manning said he didn't believe the information would harm troops in Afghanistan and Iraq or threaten national security.

Prosecutors tried to prove Manning had "a general evil intent" and knew the classified material would be seen by the terrorist group al-Qaida. Legal experts said an aiding-the- enemy conviction would set a precedent because Manning did not directly give the classified material to al-Qaida.

"Most of the aiding-the-enemy charges historically have had to do with POWs who gave information to the Japanese during World War II, or to Chinese communists during Korea, or during the Vietnam War," Duke law school professor and former Air Force judge advocate Scott Silliman said.

Manning's supporters worried that a conviction on the most serious charge would have a chilling effect on other leakers.

The verdict follows about two months of conflicting testimony and evidence. Manning admitted to sending more than 470,000 Iraq and Afghanistan battlefield reports, 250,000 State Department diplomatic cables and other material, including several battlefield video clips, to WikiLeaks while in Iraq in early 2010. WikiLeaks published most of the material online.

The video included footage of a 2007 U.S. Apache helicopter attack in Baghdad that killed at least nine men, including a Reuters news photographer and his driver.

Manning said he sent the material to expose war crimes and deceitful diplomacy. In closing arguments last week, defense attorney David Coombs portrayed Manning as a naive whistleblower who never intended for the material to be seen by the enemy.

Prosecutors called him an anarchist hacker and traitor who indiscriminately leaked classified information he had sworn to protect. They said al-Qaida leader Osama bin Laden obtained copies of some of the documents WikiLeaks published before he was killed by U.S. Navy Seals in 2011.